Watch these fascinating vintage Youtube videos
(many made before or during WWII) from the companies that made and perfected
vacuum tubes. Excellent source information.

RCA: Electrons on
Parade (Part 1)

1942 factory promo for RCA vacuum
tubes. Shows how they made the metal-can octal base tubes.

RCA: Electrons on
Parade (Part 2)

1942 factory promo for RCA vacuum
tubes. Shows how they made transmitting tubes, and many applications
from television to Tommy guns.

Vacuum Tubes: How They're Made

From the Time Life image archive of the Sylvania
Electric Factory at Emporium, PA, US 1945. The beginning audio is
from "X Minus One" an old time radio show from the '40s the rest of
the audio is tuning up and down the dial for a classic radio sound.
The Hindenburg flies over the plant for an aerial view I know the
airship Hindenburg caught fire and was destroyed on May 6, 1937 but
I thought it was a nice lead in to the Sylvania Electric Co.

Mullard Valves: The Blackburn Story
Works
History (Part 1)

Covers the history and functions of Mullard's
Blackburn Works.

Mullard Valves: The Blackburn Story

Parts of
a Valve (Part 2)

Covers all the parts that make up a valve.

Mullard Valves: The Blackburn Story

How a
Valve is Manufactured (Part 3)

Covers assembly of a valve up to
the cage stage: mica, cathode, grids and anode.

Mullard Valves: The Blackburn Story

How a
Valve is Manufactured (Part 4)

Continues coverage of the assembly
of a valve: pins, heaters and base.